The major effort during the next year will involve a coordinated study of age-related changes in specific tissue impedance, patterns of intestinal slow wave activity and mechanical properties of intestinal smooth muscle. Spontaneous and electrically driven driven slow waves, recorded from duodenum and jejunum of anesthetized aged cats will be plotted as frequency vs. propagation velocity and compared to similar data obtained from young adult animals. Tissue impedance will be determined for longitudinal and circular intestinal muscle to determine if age-related changes occur in specific myoplasmic and junctional impedance. Mechanical studies will consist of determining force-velocity and tension-length relationships of both electrically and drug-induced contractions of thin strips of circular intestinal muscle. These studies will be coupled with an electron-microscopic study of age-related changes in gastrointestinal smooth muscle.